Key aspects of the industrialization of microalgae-to-biofuel processes are: i) selection and improvements of algal strains; ii) development of high-performance photobioreactors; iii) selection of culture optimal conditions; iv) improvement of oil extraction and transesterification processes; v) development of microalgal-based biorefineries. An accurate design of nutrient selection and irradiance strategy appears to improve remarkably yield and productivity of both biomass and total lipid content). Present contribution regards the effects of both the CO2 oncentration in the gas phase and the pH of the culture medium on biodiesel production by Stichococcus bacillaris (ACUF 158/11). Two typologies of photobioreactors were investigated: 0.6 L vertical bubble column (VBC) and 1.7 L inclined bubble column (IBC). Indoor cultures of S. bacillaris were carried out under batch, fed-batch and semi-continuous conditions with respect to the liquid phase. Tests were carried out at 23°C and at continuous artificial light, irradiance 300 micronE/(m2 s). The CO2 concentration in the gas phase fed at the photobioreactors (0.5 vvm) was increased up to 15% v to simulate the CO2 concentration level in exhaust gas. The pH of the liquid culture ranged between 3.0 and 8.5. Results showed that CO2 concentration increase stimulates the microalgal growth improving the process performances when expressed in terms of biomass and lipid productivity. Tests carried out sparging gas at 5%V CO2 and at different values of pH showed that the biomass productivity is optimized at pH close to 7.0 for the investigated strain. The hydrodynamics of the two photobioreactor configurations investigated (IBC and VBC) has significant effects on the process productivity. Tests carried out in IBC photobioreactors were characterized by biomass productivity of 0.256 g/(L day) and lipid productivity 0.080 g/(L day), larger than that assessed in VBC photobioreactors, 0.124 and 0.042 g/(L day), respectively.
Biodiesel production from stichococcus bacillaris in lab-scale photobioreactors / Olivieri, Giuseppe; I., Gargano; Andreozzi, Roberto; Marotta, Raffaele; Marzocchella, Antonio; Pinto, Gabriele; Pollio, Antonino. - (2012). (Intervento presentato al convegno 2nd International Conference on Algal Biomass, Biofuels and Bioproducts tenutosi a San Diego (USA) nel 10-13 June 2012).
Biodiesel production from stichococcus bacillaris in lab-scale photobioreactors
OLIVIERI, GIUSEPPE;ANDREOZZI, ROBERTO;MAROTTA, RAFFAELE;MARZOCCHELLA, ANTONIO;PINTO, GABRIELE;POLLIO, ANTONINO
2012
Abstract
Key aspects of the industrialization of microalgae-to-biofuel processes are: i) selection and improvements of algal strains; ii) development of high-performance photobioreactors; iii) selection of culture optimal conditions; iv) improvement of oil extraction and transesterification processes; v) development of microalgal-based biorefineries. An accurate design of nutrient selection and irradiance strategy appears to improve remarkably yield and productivity of both biomass and total lipid content). Present contribution regards the effects of both the CO2 oncentration in the gas phase and the pH of the culture medium on biodiesel production by Stichococcus bacillaris (ACUF 158/11). Two typologies of photobioreactors were investigated: 0.6 L vertical bubble column (VBC) and 1.7 L inclined bubble column (IBC). Indoor cultures of S. bacillaris were carried out under batch, fed-batch and semi-continuous conditions with respect to the liquid phase. Tests were carried out at 23°C and at continuous artificial light, irradiance 300 micronE/(m2 s). The CO2 concentration in the gas phase fed at the photobioreactors (0.5 vvm) was increased up to 15% v to simulate the CO2 concentration level in exhaust gas. The pH of the liquid culture ranged between 3.0 and 8.5. Results showed that CO2 concentration increase stimulates the microalgal growth improving the process performances when expressed in terms of biomass and lipid productivity. Tests carried out sparging gas at 5%V CO2 and at different values of pH showed that the biomass productivity is optimized at pH close to 7.0 for the investigated strain. The hydrodynamics of the two photobioreactor configurations investigated (IBC and VBC) has significant effects on the process productivity. Tests carried out in IBC photobioreactors were characterized by biomass productivity of 0.256 g/(L day) and lipid productivity 0.080 g/(L day), larger than that assessed in VBC photobioreactors, 0.124 and 0.042 g/(L day), respectively.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
